Mine started and drove fine. A couple of hours later, it didn't do anything. I got all the lights, and everything looked good, but no crank. It took me an hour to figure it out as the truck wasn't someone elses; it was mine. When I pulled the top box cover off, I was awestruck at the *wittle bitty battewy* sitting in there. Took it back to the dealer after buying a new one and they said "most trucks come with those now as they turn over easier" yadda yadda yadda. I say B.S. and listen to my audiophile without the truck running, have an Edge, leave the GPS plugged in, the lights stay on for a minute after pulling in the garage and unlocking all the doors since they are on auto, (Interior, puddle, headlights, fogs and dash) and there is all the other stuff like heated seats that draw while the alternator (which is a 100amp) charges on it. I think the 100amp is a little large for a 540cca battery regardless of the regulator. After changing to an 850, I haven't had a single issue, even with the truck sitting still for a month with the GPS plugged in. As a caveat, I'd like to say I didn't leave the GPS plugged in all the time (hot) when I had the 540cca. It was too small; end of story.